Assess the damage. Pull the couch away from any other furniture and surrounding walls. Look for all bite marks, missing fabric or chewed stuffing.
Add stuffing to replace what your dog has removed. Look for a cotton or polyfill from a craft store that is similar to your couch's existing stuffing. Push the new filling into cushions or the body of your sofa and squeeze it into the correct shape. Knead the stuffing or fill into place with your hands.
Patch the couch's fabric. Use a fabric that is the same or similar to the original upholstery. Cut the fabric to size, add a thin layer of glue to the outside of the chewed area, then firmly press the patch into place. Avoid touching the patch until it is completely dry.
Sew seams or slash-type marks. Thread the needle and bring together the edges of the slice. Sew the chewed area together. Tie the loose thread at the end and cut to size.
Create a seamless look with a slipcover. Although this may mean changing the color or pattern of your couch, using a slipcover still allows you to see the original shape. Place the slipcover over the couch and tie, snap or Velcro it into place.